2.2: Brief descriptions of Microbial Pathogens
- Page ID
- 2625
Acellular pathogens: prions and viruses
1. Prions: “proteinaceous infectious particles” (see fig. 18.6/18.7 p 475 in Belk’s Biology)
-abnormally folded cellular proteins ( abbreviated “PrP’s”=Prion Proteins)
-cause Transmissible Spongiform Encephalopathies or TSE’s
-100% fatal
-prion diseases in animals (examples):
-scrapie/sheep, goats
-CWD, Chronic Wasting Disease / deer, elk;
-BSE, Bovine Spongiform Encephalopathy “Mad Cow Disease”/ cattle
-prion diseases in humans (examples):
-Kuru
-CJD, Creutzfeldt Jakob Disease
-variant vCJD (from ingestion of BSE/Mad Cow prions)
2. Viruses: “trouble wrapped in protein” (see fig 18.4 p 472 in Belk’s Biology)
-genetic info= DNA or RNA
-protein coat/capsid
+/- lipid envelope stolen from host cell
-obligate intracellular parasites; cannot replicate unless inside host cell
-e.g. smallpox/variola virus, influenza virus, herpes virus,
HIV/Human Immunodeficiency Virus, West Nile virus, Ebola virus
Fig 1: virus examples a=”naked” virus b=enveloped virus